Method for loading and drying of ceramic products prior to baking

ABSTRACT

A method of loading a plurality of formed ceramic products preparatory to baking thereof comprises positioning the products adjacent to one another in a plurality of superposed layers. The layers are formed in a plurality of successive loading steps, each of which is followed by a drying step operative to dry the uppermost layer, and to further dry previously formed underlying layers, to an extent sufficient to permit placement of a further layer on the uppermost layer without deformation of the uppermost layer or toppling of the stacked layers.

United States Patent 1 Hassler l METHOD FOR LOADING AND DRYING OFCERAMIC PRODUCTS PRIOR TO BAKING [76] Inventor: Andreas Ilassler,Jahnstrasse 45,

Erbach, Germany 22 Filed: Jan. 10, 1972 21 Appl. No.: 216,640

[30] Foreign Application Priority Data Jan. 12, 1971 Germany P 21 01073.1

[52] U.S. CI. 34/38 [51] Int. Cl. F26b 3/00 [58] Field of Search 34/31,33, 25, 38, 34/194, 204

[56] References Cited UNITED STATES PATENTS 4/1929 Cramer 34/38 X Sept.25, 1973 Primary Examiner-William F. ODea Assistant ExaminerPeter D.Ferguson Att0rneyWilliam D. Hall et al.

[5 7] ABSTRACT A method of loading a plurality of formed ceramicproducts preparatory to baking thereof comprises positioning theproducts adjacent to one another in a plurality of superposed layers.The layers are formed in a plurality of successive loading steps, eachof which is followed by a drying step operative to dry the uppermostlayer, and to further dry previously formed underlying layers, to anextent sufficient to permit placement of a further layer on theuppermost layer without deformation of the uppermost layer or topplingof the stacked layers.

6 Claims, 2 Drawing Figures BACKGROUND OF THE INVENTION Prior to bakingin tunnel kilns, ceramic products must be predried to avoid cracking andmisforming. For this purpose artificial drying means are used e.g.,drying chambers, conveyor belt or tunnel type dryers. After drying, theceramic products are loaded onto suitable trucks for baking. Arranging atunnel kiln behind one of the above mentioned drying means is expensiveespecially because of the complicated transport means necessary. Becauseof this, new forming methods were developed, using stiff or hard formedclay. The thus formedbricks, tiles etc. are loaded onto conveyorsimmediately after forming and then dried. Thereby all the layers of acomplete load are piled on a conveyor and then the complete load isdried. This method however leads to damage due to the damp and easilymisformed material being piled. For this reason drying and baking plantshave been constructed for drying and baking on a conveyor in singlelayers. Loading in single layers however is not economical because ofthe large areas involved, and the higher transport speeds which arenecessary. Such higher transport speeds lead to greater wear and tear onthe transport system.

Several attempts have been made to dry and bake bricks, tiles etc. ofsoft clay in several layers without the use of separate pre-drying.These prior attempts have, however, been unsuccessful.

It is the object of this invention to provide a method, by which it ispossible to load and to dry soft formed bricks, tiles etc. in severallayers and hard formed bricks etc. in more layers than has beenconsidered feasible heretofore, with the bricks being transferreddirectly from the mould to a conveyor or truck.

SUMMARY OF THE INVENTION To accomplish the foregoing object, the presentinvention provides a method for multi-layer loading of the foregoingceramic products, e.g. bricks, tiles etc. for drying preparatory tobaking the intermediate products into their final form. The method ischaracterized by procedure wherein the loading of each layer is followedby a drying period during which all previously loaded layers, already atleast partially dried, are respectively further dried.

As a result of the procedure, the softest layer is always the top layerand the bottom layer bearing (the greatest load) is the hardest layersince it has been dried the longest time. Thus the layers areprogressively harder from top to bottom. The layers are formed ontrucks, which are loaded periodically. There is a drying-period afterthe loading of each layer, or after loading several layers. The dryingaccomplished during each drying period is such that the last loadedlayer becomes hard enough to support the next soft layer withoutdeforming the last loaded layer. Before the next fresh layer is set intoplace, sufiicient contraction of the clay has taken place in thepreviously loaded layers to eliminate the danger'of toppling the pile.

The conveyors or trucks are loaded in at least two cycles. Each cyclemay comprise loading of more than one layer. The higher the piles themore cycles will preferably be chosen to complete the load. A number oftrucks can be loaded in each cycle, being alternately loaded and driedin layers.

In case the different layers of the pile are to be separated duringdrying, suitable fluid, granulated or solid separating means, e.g.,impregnated paper, can be. inserted between the single layers. Loadingof the bricks, tiles etc. may be performed mechanically, e.g. by knowncharging machines, or by hand. For the drier known drying means may beused.

BRIEF DESCRIPTION OF THE DRAWINGS The drawings show the dryer intwodifferent stages of the procedure, and are intended to be exemplary andnot limitative of the invention.

FIG. 1 illustrates the method of the present invention, wherein trucksin the drier having a first layer thereon are being loaded with a secondlayer.

FIG. 2 shows the trucks in the dryer loaded with four layers and beingloaded with the fifth layer.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The freshly moulded bricks,tiles etc. 2 cone from a moulding machine 1 and are loaded'by a chargingmachine 3 onto conveyors or trucks4 in a low number of layers.Subsequently each partially loaded truck is moved into a drying chamber5 after passing through the air-lock 6 located at the loading position.At the same time the following truck moves into the loading position.This cycle continues until each of the trucks 4 in the drying chamber 5are completely loaded. The completely loaded trucks or conveyors arethen passed into a waiting chamber 7, which is positioned between thedryer and the baking unit or tunnel kiln 11, and are thereaftertransported into the kiln 11 where the loads are finally baked.

A group of empty trucks is moved from a waiting room 8 to the loadingposition in the drying chamber 5 at the beginning of the loading anddrying cycle. The time for drying may be chosen according to the numberof trucks in a cycle. In the figures, conduit 9 is the hot air inlet,and conduit 10 is the hot air outlet, for the drying chamber.

The air-lock 6 separates the drying chamber 5 and the drying atmospheretherein from the surrounding atmosphere at the loading position. It is aknown airlock, and is movable up and down to prevent hot air escapingfrom the drying chamber 5 during loading.

It is also possible to have more than one loading position with a dryingchamber between two subsequent positions.

For matter of clarity only, the cycle paths of movement of the trucksare shown vertically. The paths in fact run in a horizontal plane.

What I claim is:

l. The method of loading and drying a plurality of intermediate ceramicproducts preparatory to baking thereof, comprising position saidintermediate products adjacent to one another in a plurality ofsuperposed layers on a movable support structure located within a singleclosed hot air chamber, said superposed layers being formed by aplurality of successive loading steps interspersed respectively by aplurality of drying steps, each of said loading steps being efiected byintroducing a supply of said products through an-air lock comprising aloading station located at a predetermined position adjacent said singledrying chamber to produce at least one layer of said intermediateproducts on said support structure, and each of said drying steps beingeffected by thereafter moving said support structure away from saidloading station along a predetermined close-loop path located entirelywithin said chamber and back to said loading station for the nextloading step, the time provided for the transport of said supportstructure through said closed-loop path being sufficient to dry theuppermost layer produced by the next preceding loading step and tofurther dry all underlying layers produced by prior loading steps to anextent suf ficient to prevent deformation of said previously formedlayers and to give the previously formed layers sufficient structuralrigidity to support at least one further layer of said intermediateproducts placed on said uppermost layer during the next successiveloading step.

2. The method of claim 1 including the step of placing separating meanson said uppermost layer following each loading step and prior to thenext successive loading step.

3. The method of claim 6 wherein said closed-loop path is disposed in ahorizontal plane within said drying chamber.

4. The method of claim 3 wherein said movable support structure isprovided in the form of a plurality of trucks disposed in-line with oneanother for individual transport along said closed-loop path, saidmethod including the step of moving each of said trucks in sequence tosaid loading station to receive a layer of said products, whilepreviously loaded ones of said trucks are transported along saidclosed-loop path.

5. The method fo claim 4 wherein said method includes the step ofproviding a plurality of empty trucks in awaiting area located outsideof said drying chamher, and periodically moving said empty trucks fromsaid waiting area into said drying chamber at a position on said closedloop path upstream of said loading statron.

6. The method of claim 5 including the step of diverting selected onesof said trucks out of said closed loop path and into a waiting chamberfollowing completion of the loading and drying steps associated withsaid selected trucks, and thereafter transporting said selected trucksfrom said waiting chamber along a predetermined path through a kiln toeffect baking of said products.

1. The method of loading and drying a plurality of intermediate ceramicproducts preparatory to baking thereof, comprising position saidintermediate products adjacent to one another in a plurality ofsuperposed layers on a movable support structure located within a singleclosed hot air chamber, said superposed layers being formed by aplurality of successive loading steps interspersed respectively by aplurality of drying steps, each of said loading steps being effected byintroducing a supply of said products through an air lock comprising aloading station located at a predetermined position adjacent said singledrying chamber to produce at least one layer of said intermediateproducts on said support structure, and each of said drying steps beingeffected by thereafter moving said support structure away from saidloading station along a predetermined close-loop path located entirelywithin said chamber and back to said loading station for the nextloading step, the time provided for the transport of said supportstructure through said closed-loop path being sufficient to dry theuppermost layer produced by the next preceding loading step and tofurther dry all underlying layers produced by prior loading steps to anextent sufficient to prevent deformation of said previously formedlayers and to give the previously formed layers sufficient structuralrigidity to support at least one further layer of said intermediateproducts placed on said uppermost layer during the next successiveloading step.
 2. The method of claim 1 including the step of placingseparating means on said uppermost layer following each loading step andprior to the next successive loading step.
 3. The method of claim 6wherein said closed-loop path is disposed in a horizontal plane withinsaid drying chamber.
 4. The method of claim 3 wherein said movablesupport structure is provided in the form of a plurality of trucksdisposed in-line with one another for individual transport along saidclosed-loop path, said method including the step of moving each of saidtrucks in sequence to said loading station to receive a layer of saidproducts, while previously loaded ones of said trucks are transportedalong said closed-loop path.
 5. The method fo claim 4 wherein saidmethod includes the step of providing a plurality of empty trucks inawaiting area located outside of said drying chamber, and periodicallymoving said empty trucks from said waiting area into said drying chamberat a position on said closed loop path upstream of said loading station.6. The method of claim 5 including the step of diverting selected onesof said trucks out of said closed loop path and into a waiting chamberfollowing completion of the loading and drying steps associated withsaid selected trucks, and thereafter transporting said selected trucksfrom said waiting chamber along a predetermined path through a kiln toeffect baking of said products.